Circumferential turn-down seal for flexible sector plate



P 1965 H. E. BLOSS ET AL 3,208,509

CIRCUMFERENTiAL TURN-DOWN SEAL FOR FLEXIBLE SECTOR PLATE Filed July 20. 1961 L233 1 z! 1777 i.iiy :3 T IWI"! Al i 64f I I INV EN TOR.

United States Patent 3,208,509 CIRCUMFEREN'DIA-L TURN-DOWN SEAL FOR FLEXIBLE SECTOR PLATE Harold E. Bloss and Glenn E. Flurschutz, both of Wellsville, N.Y., assignors, by mesne assignments, to The 'Air Preheater Corporation, a corporation of Delaware Filed July 20, 1961, Ser. No. 125,547 3 Claims. (Cl. 1659) The present invention relates to improvements in heat exchanger apparatus of the rotary type, and particularly to a circumferential turndown seal adapted for rotary regenerative heat exchangers that utilize a flexible sector plate being held in contact with the end of the rotor to preelude fluid flow through the space therebetween.

In rotary regenerative heat exchange apparatus a cylindrical rotor having sector shaped compartments carrying a mass of heat absorbent material is rotated alternately between spaced streams of a heating fluid and a fluid to be heated in order that heat from the heating fluid may be transferred to the fluid to be heated through the intermediary of the heat absorbent mass. The rotor is surrounded by a cylindrical housing having end or sector plates at opposite ends formed with spaced apertures between imperforate portions of sectorial configuration that provide for the independent flow of the fluids through the rotor. To prevent mingling of the heating fluid and the fluid to be heated, radial partitions of the rotor that form the sectorial rotor compartments are usually provided with radial seals arranged to Wipe against the imperforate portions of the sector plates.

In US. application No. 56,732, now US. Patent No. 3,100,014, a variation provided for a resilient end plate that is held in contact with the end of the rotor in order that the resilient end plate might flex to conform to the changing shape of the rotor as it distorts under changing thermal conditions. Certain fluid leakage around the ends of the resilient end plate and through the annular space that lies between the rotor shell and rotor housing has however defined a need beyond that of the scope of the original invention, and the chief object of this inven tion therefore is to provide a sealing arrangement that cooperates with a resilient end plate to more effectively preclude fluid flow between the rotor and its surrounding housing.

The invention will be better understood upon consideration of the following detailed description of an illustrative embodiment thereof when read in conjunction with the accompanying drawings in which:

FIGURE 1 is a sectional side elevation of a rotary regenerative heat exchanger utilizing the principles of the invention.

FIGURE 2 is a fragmentary view of an enlarged section of FIGURE 1 as seen from line 22.

FIGURE 3 is a fragmentary view on an enlarged scale of the upper circumferential sealing means as seen from line 3-3 of FIGURE 1, and

FIGURE 4 is a fragentary view on an enlarged scale of the lower circumferential sealing means as seen from line 44 of FIGURE 1.

In the drawing the numeral designates a rotor having a cylindrical rotor shell 12 divided into sector-shaped compartments by radial partitions 14 that extend between a central rotor post 16 and the rotor shell. The rotor is rotated slowly about its axis by a motor and reduction gearing arrangement that is diagrammatically illustrated at 18. The rotor compartments are filled with a mass of regenerative heat exchange material in the form of spaced metallic plates or other material that first absorbs heat from hot gases entering the heat exchanger through a duct 24 from a boiler or other source of heat to be dis- 3,208,509 Patented Sept. 28, 1965 charged after passing over the heat exchange element through an outlet duct 26 to which an induced draft fan (not illustrated) is connected. As the rotor turns slowly about its axis, the element that has been heated by the hot gases in duct 24 is moved into a stream of fluid to be heated that enters through duct 28. After passing over the elements and absorbing heat therefrom, the heated fluid is discharged through a duct 32 and directed to a boiler furnace or other point of use.

A housing 34 enclosing the rotor shell 12 is provided at either end opposite ends of the rotor shell with upper and lower end or sector plates 36 and 38 which are apertured at 42 and 44 in circumferentially spaced locations to admit and discharge streams of heating fluid and the fluid to be heated that flow through the rotor. In order that the streams of heating fluid and the fluid to be heated may not commingle, T end plates 36 and 38 have imperforate portions 46 located between the openings that are at least equal to or somewhat greater in circumferential extent than one rotor compartment. The imperforate plate 46 cooperates with the radial sealing means to isolate a single sectorial compartment when it lies between the spaced fluid passageways. In order that the fluid streams may not by-pass the rotor and flow through the annular space 48 between the rotor and rotor housing, circumferential seals are usually provided on the rotor shell 12 to cooperate with the confronting face of the adjacent end plate to seal off the annular space 48 between the rotor shell and housing from the fluids flowing through the rotor.

The development of a resilient sect-or plate 50 suspended from the imperforate surface of the end or sector plates 36 and 38 into contact with the ends of the rotor has provided an improved sealing relationship under certain conditions. However, excess distortion tends to separate the sealing leaves 52 that comprise the plate 50 and thus open a leakage path therebetween which permits the flow of fluid between the rotor compartments and the annular plenum chamber 48. This invention is therefore directed to a circumferential sealing arrangement that cooperates with a resilient sector plate to preclude fluid leakage throughout a wide range of temperature variation and rotor deformation.

In accordance with the invention an annular sealing flange 54 is secured to each end of the rotor shell 12 to provide in effect a radial extension for the plane surface formed by the end edge of the radial partitions 14 and the surrounding rotor shell. Annular wearing shoes 56 and 57 are positioned at opposite ends of the rotor housing radially outward from each sealing flange 54 to provide a mating member for the sealing flange that cooperates therewith to bridge the end edges of the plenum chamber to preclude the flow of fluid therethrough.

The sealing flange 54 is formed of steel or other hard material while the wearing shoes 56 and 57 are formed of a relatively soft material that will abrade from contact with the hard sealing flange to form a sealing surface therebetween that readily conforms to the relative deformation of the rotor and rotor housing throughout a wide range of temperature variation.

The wearing shoes are extended axially from each end plate to a point beyond the axially adjacent edge of the rotor to insure a continuous contact between the sealing flange and wearing shoe through temperature conditions that bring about substantial distortion of the rotor. Each wearing shoe is also formed with an annular inlet surface 60 that confronts the radial outer edge of each sealing flange 54 when the rotor is in a non-operating or cold condition.

As the rotor is placed in operation and the hot end adjacent the inlet for the hot gas expands outward and turns downward, the wearing shoes 56 and 57 are abraded from contact with the sealing flanges 54 to provide a particular sealing relationship therebetween for every temperature condition encountered during normal operation of the heat exchanger.

The sealing leaves 52 slidably abut the wearing shoes 56 and 57 at their radially outer ends to permit lateral flexing thereof without permitting the opening of a significant leakage path therebetween. Thus as the rotor turns down due to excessive heating at the end of the rotor that lies adjacent the inlet for the hot gas, the sealing leaves 52 adjacent thereto will expand to follow the movement of the rotor while the sealing leaves 52 at the opposite end of the rotor will be compressed to conform to the rotor distortion and thus provide a continuous sealing relationship at both ends of the rotor. Simultaneous with the shifting of the sealing leaves the sealing flange will change its position with respect to the sealing shoe so that optimum sealing conditions will obtain for any temperature condition within predetermined limits.

While this invention has been described with reference to the embodiment illustrated in the drawing, it is evident that various changes may be made without departing from the spirit of the invention, and it is intended that all matter contained in the above description or shown in the accompanying drawing shall be interpreted as illustrative and not in a limiting sense.

We claim:

1. Rotary regenerative heat exchange apparatus having a rotor including a cylindrical rotor shell joined to a rotor post by radial partitions to form a series of sectorial compartments that carry a mass of regenerative heat ex change material, a housing surrounding the rotor provided at opposite ends of the rotor with end plates having imperforate portions located between circumferentially spaced apertures that direct a heating fluid and a fluid to be heated to and through the regenerative heat exchange material carried by the rotor, sealing means between ends of the rotor and the rotor housing adapted to restrict fluid flow to the spaced apertures of the rotor comprising a resilient sector plate substantially coextensive with the imperforate portion of each end plate extending axially therefrom into sealing relation with the adjacent end of the rotor, an annular wearing member carried by the rotor housing lying radially between the resilient sector plate and the rotor housing, and a rigid annular sealing flange extending radially outward from the end edge of the rotor into sealing relationship with said wearing member whereby movement of said rotor will cause the sealing flange to abrade the adjacent surface of the wearing member to provide a sealing surface therebetween.

2. Rotary regenerative heat exchange apparatus as defined in claim 1 wherein said resilient sector plate comprises a plurality of lapped radial leaves having an axially spaced flange thereof secured to the imperforate portion of the adjacent end plate.

3. Rotary regenerative heat exchange apparatus as defined in claim 1 wherein the wearing members extend axially a distance that insures contact between the sealing flange and wearing members throughout a predetermined range of relative axial distortion.

References Cited by the Examiner UNITED STATES PATENTS 1,746,598 2/30 Ljungstrom -9 1,825,744 10/31 Boynton 285-280 X 2,631,870 3/53 Hudson 165-9 2,761,654 9/56 Valvo 1659 3,010,703 11/61 Bellows et al. 1659 3,100,014 8/63 Flurschutz 165-9 CHARLES SUKALO, Primary Examiner.

HERBERT L. MARTIN, Examiner. 

1. ROTARY REGENERATIVE HEAT EXCHANGE APPARATUS HAVING A ROTOR INCLUDING A CYLINDRICAL ROTOR SHELL JOINED TO A ROTOR POST BY RADIAL PARTITIONS TO FORM A SERIES OF SECTORIAL COMPARTMENTS THAT CARRY A MASS OF REGENERATIVE HEAT EXCHANGE MATERIAL, A HOUSING SURROUNDING THE ROTOR PROVIDED AT OPPOSITE ENDS OF THE ROTOR WITH END PLATES HAVING IMPERFORATE PORTIONS LOCATED BETWEEN CIRCUMFERENTIALLY SPACED APERTURES THAT DIRECT A HEATING FLUID AND A FLUID TO BE HEATED TO AND THROUGH THE REGENERATIVE HEAT EXCHANGE MATERIAL CARRIED BY THE ROTOR, SEALING MEANS BETWEEN END OF THE ROTOR AND THE ROTOR HOUSING ADAPTED TO RESTRICT FLUID FLOW TO THE SPACED APERTURES OF THE ROTOR COMPRISING A RESILIENT SECTOR PLATE SUBSTANTIALLY COEXTENSIVE WITH THE IMPERFORATE PORTION OF EACH END PLATE EXTENDING AXIALLY THEREFROM INTO SEALING RELATION WITH THE ADJACENT END OF THE ROTOR, AN ANNULAR WEARING MEMBER CARRIED BY THE ROTOR HOUSING LYING RADIALLY BETWEEN THE RESILIENT SECTOR PLATE AND THE ROTOR HOUSING, AND A RIGID ANNULAR SEALING FLANGE EXTENDING RADIALLY OUTWARD FROM THE EDGE OF THE ROTOR INTO SEALING RELATIONSHIP WITH SAID WEARING MEMBER WHEREBY MOVEMENT OF SAID ROTOR WILL CAUSE THE SEALING FLANGE TO ABRADE THE ADJACENT SURFACE OF THE WEARING MEMBER TO PROVIDE A SEALING SURFACE THEREBETWEEN. 